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/*
* Copyright 2018 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef SkCubicMap_DEFINED
#define SkCubicMap_DEFINED
#include "include/core/SkPoint.h"
#include "include/core/SkScalar.h"
#include "include/core/SkTypes.h"
/**
* Fast evaluation of a cubic ease-in / ease-out curve. This is defined as a parametric cubic
* curve inside the unit square.
*
* pt[0] is implicitly { 0, 0 }
* pt[3] is implicitly { 1, 1 }
* pts[1,2].X are inside the unit [0..1]
*/
class SK_API SkCubicMap {
public:
SkCubicMap(SkPoint p1, SkPoint p2);
static bool IsLinear(SkPoint p1, SkPoint p2) {
return SkScalarNearlyEqual(p1.fX, p1.fY) && SkScalarNearlyEqual(p2.fX, p2.fY);
}
float computeYFromX(float x) const;
SkPoint computeFromT(float t) const;
private:
enum Type {
kLine_Type, // x == y
kCubeRoot_Type, // At^3 == x
kSolver_Type, // general monotonic cubic solver
};
SkPoint fCoeff[3];
Type fType;
};
#endif
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